Women are exposed to several botanical compounds through their diet or because they are being used as agents to prevent or treat a variety of conditions, including cancer, kidney disease, neuronal injury, sexual dysfunction, inflammation, depression, and menopausal symptoms. While studies indicate that botanical compounds may be useful in treating some adverse conditions, the side effects are less well understood. Unfortunately, very few studies have examined the effects of botanical compounds such as soy products (genistein, equol), licorice root (isoquiritigenin), and horny goat weed (icariin) on ovarian function. Thus, the goal of the proposed studies is to use an adult mouse model to test the hypothesis that selected botanical compounds (i.e., soy products (genistein, equol), licorice root (isoquiritigenin), and horny goat weed (icariin)) decrease estradiol (E2) synthesis and/or increase E2 metabolism, leading to decreased E2 levels; and that the decreased E2 levels lead to slow follicular growth and atresia. To test this hypothesis, we propose the following two specific aims: 1) determine whether selected botanical compounds cause low E2 levels by inhibiting expression of enzymes required for E2 synthesis and/or inducing expression of the enzymes involved in metabolism of E2 in antral follicles and 2) determine whether selected botanical compounds cause slow growth and/or increased atresia of antral follicles. The results from the proposed studies will provide novel and important information on the effects of botanical compounds on the adult ovary. This information will be useful for determining the risks and benefits of botanical chemicals. 2